Devices, systems and methods for accurate positioning of a prosthetic valve

ABSTRACT

The invention is a system and method for accurately positioning a prosthetic valve such as a prosthetic heart valve at a desired position for deployment. The invention includes extendable positioning elements which provide tactile feedback to a user to confirm proper positioning of the catheter with respect to the native valve annulus. During delivery, the extendable positioning elements lie against the catheter, over the prosthetic valve and expandable balloon, providing a low profile for advancing the catheter to the desired treatment location via small passages such as body lumens. Prior to valve deployment, the positioning elements are extended and brought into contact with tissue of the native annulus to confirm the proper positioning of the delivery system and prosthetic valve.

RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119(e) to U.S.Provisional Application Ser. No. 61/478,109, filed Apr. 22, 2011.

FIELD OF THE INVENTION

The present invention relates to methods and devices for delivering avalve prosthesis for implantation in body channels, including, but notlimited to, a cardiac valve prosthesis to be implanted by surgicalprocedures such as open surgery, percutaneous procedures such astranscutaneous catheterization, and endoscopic minimally invasivesurgery. The valve prosthesis can be also applied to other body channelsprovided with native valves, such as veins or in organs (liver,intestine, urethra, etc.).

BACKGROUND OF THE INVENTION

The present invention relates to systems used to deliver a prostheticvalve to a heart. More specifically, the present invention is directedto an improved delivery system for delivery of a prosthetic valve to ahuman heart.

Catheters for prosthetic heart valve implantation are known in the artand have been commonly used to reach locations inside the body that arenot readily accessible by surgery or where access without surgery isdesirable. Numerous transcatheter techniques are known in the art,including techniques which are percutaneous, trans-arterial,trans-venous, trans-cardiac, trans-atrial, trans-ventricular, and/ortrans-apical. A key factor in such transcatheter heart valve deploymentis properly positioning the prosthetic implant, e.g., accuratelypositioning a prosthetic heart valve within the native heart valveannulus.

Over the years, a variety of techniques have been proposed and/or usedfor facilitating proper positioning of catheters. For example, currenttranscatheter valve implantation systems, such as the Edwards SAPIEN™Transcatheter Heart Valve, use fluoroscopy and/or echography to properlyposition the valve within the native valve annulus prior to deployment.Such imaging modalities involve extensive and complicated equipment, andmay also have limitations in their accuracy in some circumstances.Improvements may be desired which, when compared to known techniques,may provide improved accuracy, reduced cost/complexity, and/or backuppositioning (when used in combination with known techniques).

Prior art methods also include modifications to the implant itself. Forexample, some transcatheter valve implantation systems employretractable metal positioners that extend from the valve frame. Forexample, U.S. Pat. Nos. 7,201,772 and 7,399,315, as well as US PatentPublication No. 2008/0071362, disclose the use of positioners which arean integral component of the prosthetic heart valve frame. Thepositioners add extra material to the prosthetic heart valve. Also, upondeployment of the prosthetic heart valve in the patient, the positionersremained in the patient.

Another approach includes the filling (via injection, etc.) of a portionof the prosthetic implant itself with a radiographic contrast solution.After the surgeon or other user has properly positioned and deployed theimplant, the radiographic contrast solution is pumped out and replacedwith a hardening agent which increases the stiffness of the implant inorder to aid in retaining the implant at the desired position. Such atechnique is relatively complex.

Although a variety of prosthetic valve positioning methods and systemshave been proposed over the years, each of the existing methods andsystems has shortcomings. Additionally, improved methods and systems maybe used in combination with previously-known methods in order to achieveimproved accuracy and/or reliability. Accordingly, an urgent need existsfor an improved valve positioning method and system which is versatile,reliable, and easy to use. The present invention addresses this need.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide a heart valvedelivery system for delivery of a prosthetic (i.e., replacement) heartvalve to a native valve site within the human vasculature. The deliverysystem includes a delivery catheter having one or more extendablepositioning limbs configured to be selectively and radially extendedfrom the catheter body.

In an exemplary embodiment of the invention, positioning elements areincorporated into the valve delivery catheter itself. The positioningelements may be configured to be radially expanded and/or longitudinallydisplaced with respect to other elements of the valve delivery catheter.

In one exemplary embodiment of the invention, a prosthetic heart valveis positioned on a distal portion of a delivery catheter. One or moreextendable limbs are also positioned on the delivery catheter. Eachextendable limb extends from a fixed end to a free end, with the fixedend secured to the delivery catheter. The fixed end is secured to thedelivery catheter at a position which is longitudinally displaced fromthe prosthetic heart valve, with the free end positioned longitudinallyadjacent the prosthetic heart valve, such that the extendable limbextends over at least a portion of the length of the prosthetic heartvalve. The extendable limb is configured to transform from a restrainedposition wherein the free end is positioned tightly against the catheterbody to an extended position wherein the free end is radially extendedaway from the catheter body.

The extendable limbs may be spring-loaded or otherwise configured suchthat, when the limb is radially unrestrained, the free ends thereof willrevert to a position wherein the free ends are radially extended awayfrom the catheter body. For example, the extendable limbs may be formedfrom a memory material.

A sliding cuff may be used to restrain the extendable limbs. The slidingcuff may be configured to slide over the extendable limbs starting froma position adjacent the fixed ends of the extendable limbs, with thesliding cuff configured to be slid over the extendable limbs in adirection toward the free ends thereof. The sliding cuff may have aninternal diameter sized to permit the sliding cuff to be slid over thecatheter and extendable limbs in a relatively tight fashion, such thatas the sliding cuff is slid over the extendable limbs the limbs areforced to assume their restrained position wherein the free ends thereofare positioned radially against the catheter.

In one example of a method according to the invention, a prostheticheart valve is configured for deployment using a balloon. For example,the prosthetic heart valve may comprise a balloon expandable stentsupporting a bioprosthetic valve. A delivery catheter may include anexpandable balloon at a distal portion of the catheter. Prior toimplantation, the prosthetic heart valve is carefully crimped onto theballoon of the delivery catheter of the invention. The positioners, inthe form of retractable members, are positioned at least partially overand tightly against the prosthetic valve, such that the overall profileof the catheter distal portion (with expandable balloon, prostheticvalve, and positioners) is relatively low in order to promote easyadvancement of the catheter through the body lumen(s). The catheterdistal portion (with prosthetic valve thereon) can then be advanced tothe desired position for valve deployment. For example, for replacing anaortic valve, the catheter distal portion may be advanced into thepatient via the femoral artery and delivered to a native stenotic aorticvalve using a retrograde approach, or may be advanced into the patientvia an intercostal or other chest opening and into the left ventricularapex to the native stenotic aortic valve using an antegrade approach.

Once the catheter distal portion with prosthetic valve thereon ispositioned at the native valve annulus, the positioners are used torefine the positioning. In one embodiment of the invention, the catheterdistal portion is advanced distally until the prosthetic heart valvepasses through the native valve annulus. The retractable members arethen radially deployed away from the catheter. The catheter distalportion is then retracted proximally at least partially back through thenative valve annulus until the retractable members engage against thenative valve leaflets, valve annulus, and/or other structures. The userthen knows that the prosthetic heart valve is at the desired position.The user can then deploy the prosthetic heart valve at the desiredposition within the native valve annulus. In one embodiment of theinvention, the retractable members are pressed between the prostheticheart valve and native valve annulus when the prosthetic heart valve isdeployed. In such an embodiment, after the prosthetic heart valve isproperly deployed the catheter distal portion can be advanced once againdistally a distance sufficient for the retractable members to slip freeof the deployed prosthetic heart valve and native valve annulus. Theretractable members are then radially retracted against the catheterdistal portion (i.e., to their retracted/delivery state), and the entirecatheter assembly can be withdrawn from the heart valve, heart, andpatient, leaving the prosthetic valve in proper placement in the heart.

In one embodiment of the invention, after the accurate positioning thecatheter within the valve annulus using the retractable member, butprior to actual deployment of Patent Application the prosthetic heartvalve, the retractable members are advanced distally away from theprosthetic heart valve. This advancement of the retractable membersoccurs while the rest of the catheter remains stationary, i.e., with theprosthetic heart valve held in the desired position for deployment asdescribed above. To distally advance the retractable members whileholding the catheter stationary requires the retractable members to beconfigured for distal displacement with respect to the rest of thecatheter, including the portion to which the prosthetic heart valve issecured. For example, the retractable members may be secured to asliding assembly which permits the retractable members to be distallyadvanced with respect to the expandable balloon and/or other structuresto which the prosthetic heart valve is held on the catheter. In such anembodiment, after the retractable members are advanced distally (butwith the prosthetic heart valve still at the selected and accuratedeployment position), valve is properly deployed (e.g., by expanding avalve deployment balloon). The retractable members can be radiallyretracted just before, during, or just after deployment of theprosthetic valve. After the valve is deployed, and with the retractablemembers radially retracted to their retracted position, the entirecatheter assembly can be withdrawn from the heart valve, heart, andpatient, leaving the prosthetic valve in proper placement in the heart.

The system is well suited for advancing a prosthetic valve into theheart via one or more blood vessels such as the aorta and/or femoralartery, preferably with the retractable members retracted duringadvancement through the aorta and/or femoral artery and/or other bodylumen, but with the retractable members then extended when the systemhas advanced the prosthetic heart valve to a position at or adjacent thenative valve annulus. The system is also well suited for advancing aprosthetic valve into the heart via a surgically-created opening in theheart wall such as an apical puncture, preferably with the retractablemembers retracted during advancement through the apical puncture, butwith the retractable members then extended when the system has advancedthe prosthetic heart valve to a position at or adjacent the native valveannulus.

The catheter with prosthetic heart valve and retractable members may beadvanced into the heart from a position upstream or downstream of thenative heart valve being replaced. The retractable members may beadvanced in an expanded configuration toward the native heart valveannulus from a position upstream or downstream of the native heartvalve.

A further understanding of the nature and advantages of the presentinvention are set forth in the following description and claims,particularly when considered in conjunction with the accompanyingdrawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the present invention will become appreciatedas the same become better understood with reference to thespecification, claims, and appended drawings wherein:

FIG. 1 is a perspective view of a system for replacing a deficient valveaccording to an embodiment of the invention;

FIGS. 2A-2B depict side and distal end views, respectively, of a distalportion of the system of FIG. 1, with the system in the deliveryconfiguration, according to an embodiment of the invention;

FIGS. 3A-3B depict side and distal end views, respectively, of thesystem of FIGS. 2A-2B, with the positioning members extended;

FIGS. 4A-4B depict side and distal end views, respectively, of thesystem of FIGS. 2A-2B, with the balloon expanded to deploy theprosthetic valve;

FIG. 5 depicts a side view of a distal portion of a system for replacinga deficient valve, with the positioning members fully extended,according to an embodiment of the invention;

FIG. 6A depicts a side view of a distal portion of a system forreplacing a deficient valve according to an embodiment of the invention;

FIG. 6B depicts a side view of the system of FIG. 6A, with a distal endportion of the device extended telescopically from rest of the distalportion;

FIGS. 7A-7B depict side views of a distal portion of a system forreplacing a deficient valve according to an embodiment of the invention;

FIGS. 8A-8B depict side views, respectively, of a distal portion of asystem for replacing a deficient valve according to an embodiment of theinvention;

FIGS. 9A-9B depict cross-sectional views through the left side of apatient's heart showing a prosthetic valve being delivered and deployedto a native valve annulus via a retrograde approach according to anembodiment of the invention;

FIGS. 10A-10B depict cross-sectional views through the left side of apatient's heart showing a prosthetic valve being delivered and deployedto a native valve annulus via an antegrade transapical approachaccording to an embodiment of the invention;

FIGS. 11A-11B depict cross-sectional views through the left side of apatient's heart showing a prosthetic valve being delivered and deployedto a native valve annulus via a retrograde approach according to anembodiment of the invention;

FIGS. 12A-12B depict cross-sectional views through the left side of apatient's heart showing a prosthetic valve being delivered and deployedto a native valve annulus via an antegrade transapical approachaccording to an embodiment of the invention; and

FIGS. 13A-13B depict side (in partial cross-section) and distal endviews, respectively, of a distal portion of a device according to anembodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 depicts a delivery system 10 configured to deliver a prostheticimplant such as a prosthetic valve 12 to a selected position using adelivery catheter 14. The delivery catheter 14 comprises a generallyelongated catheter main body 16. A catheter distal portion 18 terminatesat a catheter distal end 20, and a catheter proximal portion 22terminates in a catheter proximal end 24. The catheter proximal portion22 includes a catheter handle 26 which may have one or more controls 27,28, 29.

The catheter main body 16 may have a usable length (i.e., from thedistal end of the handle 26 to the catheter distal end 20) sufficient topermit a user to advance the catheter distal portion 18 with prostheticvalve 12 thereon to a desired position within the patient while thecatheter handle 26 remains accessible to the user at a position outsideof the patient. For a catheter for delivering a heart valve via atransfemoral approach (via the femoral artery and aorta), the catheter14 may have a usable length sufficient to reach from an incision in thepatient's leg, through the femoral artery, through the aorta, and intothe aorta. For such a procedure the catheter usable length may be about130 cm. With a catheter for delivering a heart valve via an apicalapproach (e.g., via an intercostal incision in the chest wall and thenthru a puncture in the heart apex), the catheter may have a usablelength of about 24 inches or less.

The catheter distal portion 18 includes an implant holding section 30 towhich the prosthetic valve 12 is positioned. In the particularembodiment depicted, the implant holding section is a catheter balloon32 configured to be selectively expanded to an enlarged diameter tothereby expand the prosthetic valve 12 to its enlarged/deployeddiameter, whereby the prosthetic valve 12 is expanded into contact withthe native valve annulus.

Note that the catheter distal portion may include a sheath configured tobe slid over the prosthetic valve in its unexpanded/delivery diameter.For a self-expanding prosthetic valve (e.g., a prosthetic valve having asupport stent biased to self-expand to an expanded/deployed diameterwhen released from a restrained/unexpanded configuration, such as asupport stent formed from a memory material such as Nitinol), the sheathrestrains the prosthetic valve in its unexpanded/delivery diameter. Thesheath is further configured to be slid off of the prosthetic valve torelease the prosthetic valve. For a self-expanding prosthetic valve,sliding the sheath off of the valve permits the support stent toself-expand to its enlarged/deployment diameter. The sheath may be inaddition to or in lieu of an expandable balloon such as that depicted inFIG. 1.

The catheter 14 further comprises a positioner 34 positioned at thecatheter distal portion 18. The positioner 34 comprises one or moremembers 36 which can be radially extended from and/or retracted againstthe catheter distal end 18.

A user may control operation of the balloon 32, positioner 34, and/orsheath by movement or other activation of one or more of the controls27, 28, 29 on the handle 26. For example, a first control 27 maycontrol, via sliding movement thereof, extension and/or retraction ofthe retractable member 36 of the positioned 34. A second control 28 maycontrol, via sliding movement, the sliding advancement/retraction of thesheath. A third control 29 may control the flow of fluid into and/or outof the balloon 32 to inflate and/or deflate the balloon 32.

FIGS. 2A-2B depict close-up views of the catheter 14 of FIG. 1, andparticularly of the catheter distal portion 18. The prosthetic valve 12comprises a support stent 38 surrounding prosthetic valve leaflets 40.The prosthetic valve 12 is tightly crimped onto the expandable balloon32.

The retractable members 36 each have a fixed end 42 secured to thecatheter distal portion 18 at a fixed end attachment point 44 which isdistal of the implant holding section 30 and of the prosthetic valve 12.The retractable members 36 each have a free end 46, which may be roundedat the tip to prevent unnecessary trauma to tissue when the free end 46is pressed against same. In the particular embodiment depicted, theretractable members 36 are in their retracted/unexpanded configuration,and extend proximally from the fixed end attachment point 44 to the freeend 46. The free end 46 is positioned radially adjacent the catheterdistal portion 18 at a position overlying the prosthetic valve 12 andimplant holding section 30/expandable balloon 32. In the particularembodiment depicted, when in the retracted position the free end 46 ispositioned longitudinally adjacent the middle third portion 47 of theprosthetic valve 12 and also of the middle third portion 49 of theexpandable balloon 32 (which in the particular embodiment depictcoincides with a middle third portion of the implant holding section30), with the body of the retractable member 36 passing over a valveannulus alignment position 51 along the length of the prosthetic heartvalve 12 which is intended to be aligned with structure of the valveannulus (or other target tissue) against which the member free ends willengage when positioning the device. In a preferred embodiment of theinvention, the retractable member 36 has a member length 48 from fixedend attachment point 44 to free end 46 of about 10 to 15 mm.

In the particular embodiment of FIGS. 2A-2B, the catheter 14 includes acuff 50 configured to be slidingly advanced over and with respect to theretractable members 36. In the embodiment of FIGS. 2A-2B, the cuff 50 ispositioned over the retractable members 36, thus holding the retractablemembers 36 in their retracted/unexpanded position such that theretractable members 36 are held against and generally parallel to thecatheter distal portion 18, with the free ends 46 positioned radiallyadjacent the prosthetic valve 12 and balloon 32.

As depicted in FIGS. 3A-3B, the cuff 50 can be slid distally, thusextending the retractable members 36 away from the catheter 14. Theretractable members 36 may be spring-loaded or otherwise biased (e.g.,via memory materials, etc.) toward their extended configuration, and/ormay be configured to be mechanically extended to the extendedconfiguration via other means known in the art. The free ends 46 of theretractable members 36 are positioned a radial distance 52 away from theradial center 54 of the catheter proximal portion, and are also alignedlengthwise with the alignment position 51 of the prosthetic valve 12.

In one exemplary embodiment of the invention for use with implanting aprosthetic heart valve, the radial distance 52 when the members 36 areretracted (as depicted in FIG. 2A) is about the same as, or justslightly larger than (in order to lie flat on the surface of the valve),the radius of the prosthetic valve when the valve is mounted on thecatheter in its crimped/unexpanded/predeployment configuration. Forexample, for a prosthetic valve which in its unexpanded state has adiameter of 8 mm (i.e., a radius of 4 mm), the radial distance 52 wouldbe about 4mm or slightly more (e.g., 5 mm). When the members 36 areextended, such as depicted in FIGS. 3A-3B, the radial distance 52 wouldbe about the same as the radius (i.e., one-half of the diameter) of thenative heart valve annulus, or slightly larger so that the free ends 46of the retractable members 36 engage against tissue adjacent theannulus. In an exemplary embodiment, the retractable members when fullyextended define a diameter of about 15 mm to 35 mm, so that the radialdistance 52 is about 7 mm to 18 mm. Note that other sizes are alsowithin the scope of the invention.

The retractable members 36 serve as guides for the user to determine ifthe catheter 14 is properly positioned such that the prosthetic valve 12is properly aligned with the native valve annulus. Once the userdetermines that the prosthetic valve 12 is in proper position fordeployment, he/she can expand the balloon 32 to expand the support stent38 to its expanded/deployed diameter and thereby deploy the prostheticheart valve 12, as depicted in FIGS. 4A-4B.

The retractable members may be configured (via spring-loading, hingeconnection, and/or memory materials) to assume a somewhat L-shapedand/or curved configuration when extended to their deployedconfiguration. For example, as depicted in FIG. 5, a catheter 14 has aretractable member 36 (which may have been generally straight from freeend to fixed end when in the restrained/unexpanded condition such as inthe embodiment depicted in FIGS. 2A-2B) which may include one or morebend/hinge points 56 along its length between generally straightsegments 36 a, 36 b when in an expanded configuration. With theretractable members 36 fully extended and the balloon 32 expanded, thefree-end adjacent segment 36 a is generally parallel to and adjacent theexpanded balloon 32 (and also generally parallel to the catheter distalportion 18), while the fixed-end adjacent segment 36 b is angled sharplyaway from the catheter distal portion 18 to position the free-endadjacent segment 36 a at the desired radial distance 52 from the radialcenter 54. With such a configuration, the free-end adjacent segment 36 acan be pressed between the native valve annulus and prosthetic valve 12when the balloon 32 is expanded, but without substantially interferingwith the radial expansion of the prosthetic valve 12 and its supportstent 38. Moreover, the free-end adjacent segment 36 a, due to itsgenerally parallel orientation, can also be somewhat easily slid outfrom between the native valve annulus and deployed prosthetic valve 12.

A catheter according to the invention may comprise materials to enhancevisibility with various medical imaging techniques, such as fluoroscopy,ultrasound, magnetic resonance, etc. For example, the catheter 14 mayinclude one or more markers for enhanced visibility, such as radiopaquemarkers, at various positions. In a preferred embodiment, radiopaquemarkers 58 are included at the free ends 46 of the retractable members36, as depicted in FIG. 5. The radiopaque markers 58, which are moreradiopaque than other portions of the catheter assembly, may assist theuser to more clearly see exactly where the retractable members 36 andtheir associated free ends 46 are positioned. The user can also use theradiopaque marker 58 to visually confirm that the retractable members 36are radially expanded.

In another embodiment of the invention, depicted in FIGS. 6A-6B, thecatheter 14 includes a slidingly-movable portion 60 which includes thefixed end attachment point 44 to which the fixed end 42 of theretractable member 36 is secured. The slidingly-movable portion 60 canbe advanced distally away from (for an embodiment such as depicted inFIGS. 2A-4B) or proximally away from (for an embodiment such as depictedin FIGS. 7A-8B) the implant holding section 30 and/or balloon 32 withoutrequiring movement of the rest of the catheter 32. In a method of usingsuch an embodiment, the user can extend the retractable member(s) 36 toan expanded/deployed position, depicted in FIG. 6A, and use the deployedmember(s) 36 to properly position the implant holding section 30 and/orballoon 32 (with prosthetic valve 12 thereon) at the desired deploymentlocation. Once the desired deployment location is achieved, the catheter12 can be held stationary to keep the (still undeployed) prostheticvalve 12 at the desired deployment location, while the slidingly-movableportion 60 is slid away, via a longitudinally extendable support rod 62,from implant holding section 30 and/or balloon 32 (with prosthetic valve12 thereon) until the retractable members 36 are largely or entirelyclear, with respect to the length of the catheter 12, of the implantholding section 30 and/or balloon 32 (with prosthetic valve 12 thereon),as depicted in FIG. 6B. The prosthetic valve 12 is deployed to itsexpanded configuration, e.g., by expanding the balloon 32. Note that theexpanded balloon 32 and prosthetic valve 12 are clear of the retractablemembers 36 and the free ends 46 thereof. Before, during, or afterdeployment of the prosthetic valve 12 and/or expansion of the balloon32, the retractable members 36 can be retracted to theirunexpanded/delivery figuration. With the prosthetic valve 12 deployed,the balloon 32 can be deflated, and the catheter 12 (with deflatedballoon and retracted retractable members) can be withdrawn from thepatient through the now-deployed prosthetic valve 12.

In the embodiments depicted above, the retractable members were securedwith their fixed ends distal of the implant holding section. In otherembodiments, however, such as those depicted in FIGS. 7A-7B, theretractable members 36 are secured with their fixed ends 42 secured tothe catheter distal portion 18 at fixed end attachments points 44 whichare proximal of the implant holding section 30, balloon 32, andprosthetic valve 12. When in a retracted configuration (i.e., deliveryand/or removal configuration) such as that depicted in FIG. 7A, the freeend 46 is positioned radially adjacent the catheter distal portion 18 ata position overlying the prosthetic valve 12 and implant holding section30/expandable balloon 32. In the particular embodiment depicted, thefree end 46 is also positioned longitudinally adjacent the middle thirdportion 47 of the prosthetic valve 12 and also of the middle thirdportion 49 of the expandable balloon 32 (which in the particularembodiment depict coincides with a middle third portion of the implantholding section 30). When the retractable members 36 are deployed to thelarger deployed configuration, the free ends 46 are in longitudinalalignment with the tissue alignment position 51 of the prosthetic valve.

While the above embodiments have depicted an implant such as aprosthetic valve being deployed using a balloon catheter, otherdeployment methods and devices are also within the scope of theinvention. For example, a prosthetic valve 12 or other implant may be aself-expanding device restrained by a sheath 70 configured to be slidover all or a portion of the implant holding section 30 to restrain theprosthetic valve 12 therein, as depicted in FIG. 8A, for delivery of theprosthetic valve 12 to the treatment site. The retractable members 36can be extended to assist in accurately positioning the prosthetic valve12, and the sheath 70 can then be slidingly retracted from the implantholding section to release the prosthetic valve 12, which thenself-expands, as depicted in FIG. 8B. The self-expanding supportstructure 38 of the prosthetic valve 12 thus expands into contact withthe native valve annulus.

FIGS. 9A-9B depict a catheter 14 (similar to that depicted in FIGS.2A-2B) delivering a prosthetic valve 12 into a heart 80 for deploymentwithin the native valve annulus 82 via a retrograde approach accordingto an embodiment of the invention. The catheter 14 is advanced into thepatient via the femoral artery (not shown) and then through the aorta 84and aortic sinus 88, through the native valve annulus 82 and nativevalve leaflets 86, and into the left ventricle 90. Once the free ends 46of the retractable members 36 have cleared the valve annulus 82, asdepicted in FIG. 9A, the retractable members 36 can be deployed/radiallyextended. The user can then slowly retract the catheter 14 until thefree ends 46 contact the native valve annulus 82, native valve leaflets86, and/or other valve or valve-adjacent tissue, as depicted in FIG. 9B.Using tactile feedback from the catheter 14 created by the contact ofthe free ends 36 with the valve tissue and/or valve-adjacent tissue, theuser can confirm the proper positioning of the prosthetic valve 12. Withthe proper positioning confirmed, the user can expand the balloon 32 orotherwise (e.g., via removal of a restraining sheath, etc.) effectuateexpansion/deployment of the prosthetic valve 12 into the desiredposition within the native valve annulus 82. The retractable members 36are retracted back to their restrained/unexpanded configuration, theballoon 32 is deflated to a reduced diameter, and the catheter 14 isthen withdrawn from the heart, leaving the prosthetic valve deployedwithin the heart.

Note that the user may rely on additional positioning techniques, suchas fluoroscopy, echocardiography, etc. For example, during initialadvancement of the catheter into the heart, the user may usefluoroscopic, echocardiagraphic, and/or other imaging methods to providevisual confirmation of the orientation and position of the catheter,prosthetic valve, and/or positioning elements relative to the nativevalve annulus or other deployment site. The user may also use thefluoroscopic, echocardiagraphic, and/or other imaging methods to providevisual confirmation of the orientation and position of various elementsof the delivery system in addition to the tactile feedback provided bythe positioning elements, e.g., during the positioning of the devicedescribed herein using the positioning elements. The tactile feedbackthus provides the operator with another important sensory cue to therelative position of the positioning elements/prosthetic valve withrespect to the native valve annulus.

While the specific methods discussed above address replacement of anaortic valve, the invention can be used to aid in the accuratepositioning and deployment of implants relative to all cardiac valves,as well as relative to other orifices and body lumens, such as theorifices of all the major arteries and veins related to the heart(including but not limited to the superior and inferior vena cavae,pulmonary arteries and veins, coronary sinus, inominate artery, commoncarotid arteries, and subclavian arteries.

FIGS. 10A-10B depict a catheter 14 (similar to that depicted in FIGS.2A-2B) delivering a prosthetic valve 12 into a heart 80 for deploymentwithin the native valve annulus 82 via an antegrade approach accordingto an embodiment of the invention. The catheter 14 is advanced into thepatient via an intercostal incision (not shown) and then through apuncture 92 in the apex 94 of the heart 80 and into the left ventricle90. The catheter 14 is then advanced through the native valve annulus 82and native valve leaflets 86, and into the aortic sinus 88 and aorta 84.Once the free ends 46 of the retractable members 36 have cleared thevalve annulus 82, as depicted in FIG. 10A, the retractable members 36can be deployed/radially extended. The user can then slowly retract thecatheter 14 until the free ends 46 contact the native valve annulus 82,native valve leaflets 86, and/or other valve or valve-adjacent tissue,as depicted in FIG. 10B. Using tactile feedback from the catheter 14created by the contact of the free ends 36 with the valve tissue and/orvalve-adjacent tissue, the user can confirm the proper positioning ofthe prosthetic valve 12. With the proper positioning confirmed, the usercan expand the balloon 32 or otherwise (e.g., via removal of arestraining sheath, etc.) effectuate expansion/deployment of theprosthetic valve 12 into the desired position within the native valveannulus 82. The retractable members 36 are retracted back to theirrestrained/unexpanded configuration, the balloon 32 is deflated to areduced diameter, and the catheter 14 is then withdrawn from the heart,leaving the prosthetic valve deployed within the heart. The apicalpuncture 92, intercostal incision, and other incisions are closed (e.g.,via suturing) to complete the procedure.

FIGS. 11A-11B depict a catheter 14 (similar to that depicted in FIGS.7A-8B) delivering a prosthetic valve 12 into a heart 80 for deploymentwithin the native valve annulus 82 via a retrograde approach accordingto an embodiment of the invention. The catheter 14 is advanced into thepatient via the femoral artery (not shown) and then through the aorta 84to a position where the retractable members 36 are in the coronary sinus88 and just short of the native valve annulus 82 and native valveleaflets 86. The distal end 18 of the catheter 14 may be positioned justshort of, within, or through the native valve annulus 82. Theretractable members 36 (which extend with the free ends 36 thereoffacing distally with respect to the catheter 12) are thendeployed/radially extended, as depicted in FIG. 11A. The user can thenslowly advance the catheter 14 until the free ends 46 contact the nativevalve annulus 82, native valve leaflets 86, and/or other valve orvalve-adjacent tissue, as depicted in FIG. 11B. Using tactile feedbackfrom the catheter 14 created by the contact of the free ends 36 with thevalve tissue and/or valve-adjacent tissue, the user can confirm theproper positioning of the prosthetic valve 12. With the properpositioning confirmed, the user can expand the balloon 32 or otherwise(e.g., via removal of a restraining sheath, etc.) effectuateexpansion/deployment of the prosthetic valve 12 into the desiredposition within the native valve annulus 82. The retractable members 36are retracted back to their restrained/unexpanded configuration, theballoon 32 is deflated to a reduced diameter, and the catheter 14 isthen withdrawn from the heart, leaving the prosthetic valve 12 deployedwithin the heart.

FIGS. 12A-12B depict a catheter 14 (similar to that depicted in FIGS.7A-7B) delivering a prosthetic valve 12 into a heart 80 for deploymentwithin the native valve annulus 82 via an antegrade approach accordingto an embodiment of the invention. The catheter 14 is advanced into thepatient via an intercostal incision (not shown) and then through apuncture 92 in the apex 94 of the heart 80 and into the left ventricle90. The catheter 14 is then advanced toward the native valve annulus 82and native valve leaflets 86, but stopping with the free ends 46 of theretractable members 36 just short thereof. With the free ends 46 justshort of the native valve annulus 82, as depicted in FIG. 12A, theretractable members 36 can be deployed/radially extended. The user canthen slowly advance the catheter 14 until the free ends 46 contact thenative valve annulus 82, native valve leaflets 86, and/or other valve orvalve-adjacent tissue, as depicted in FIG. 12B. Using tactile feedbackfrom the catheter 14 created by the contact of the free ends 46 with thevalve tissue and/or valve-adjacent tissue, the user can confirm theproper positioning of the prosthetic valve 12. With the properpositioning confirmed, the user can expand the balloon (not shown) orotherwise (e.g., via removal of a restraining sheath, etc.) effectuateexpansion/deployment of the prosthetic valve 12 into the desiredposition within the native valve annulus 82. The retractable members 36are retracted back to their restrained/unexpanded configuration, theballoon is deflated to a reduced diameter, and the catheter 14 is thenwithdrawn from the heart 80, leaving the prosthetic valve 12 deployedwithin the native valve annulus 82. The apical puncture 92, intercostalincision, and other incisions are closed (e.g., via suturing) tocomplete the procedure.

Other devices and methods are also within the scope of the invention, aswell is the use of various materials to form aspects thereof. Forexample, the retractable members may be formed from materials such asmetal and/or plastic. The retractable members may be attached to thedelivery catheter through an inner lumen, with a control line passingthrough the inner lumen back to the handle and to the retractable membercontrols. The number of retractable members extending from the cathetermay range from 1 to 16 or more. The retractable members may be equallyspaced about the circumference of the catheter body. The retractablemembers may be spring-loaded or otherwise biased toward an expandedconfiguration, such that releasing them from a restrained configuration(such as by withdrawing a restraining sheath, or advancing the membersout of a lumen) results in deployment of the retractable membersradially outward from the catheter body. The retractable members may beinflatable, wherein when uninflated they lie generally flat against thecatheter but when inflated they assume their expanded/deployedconfiguration with the free ends displaced radially away from thecatheter body. The retractable members may be deployed and/or retractedusing a combination of the above-discussed methods. For example, memberdeployment could be achieved via spring-loading and/or memory aspects ofthe member material, while member retraction could be achieved byretracting the members into a restraining sheath.

The retractable members may have rounded free ends to prevent tissuetrauma from contact with the free ends. For example, the retractablemembers may be looped structures, similar in form to a wire kitchenwhisk, forming smooth, rounded contact surfaces on the free ends of eachretractable member.

In a further embodiment depicted in FIGS. 13A-13B, the retractablemembers 36 of a catheter 14 may all be interconnected, or tethered, toeach other via one or more tethers 100, 102, so that when theretractable members 36 are expanded the resulting contact surface 104presented to the native valve annulus (or other tissue) by the tether102 connecting the free ends 46 is a smooth, circular surface. Theoverall structure created by the deployed retractable members 36 andtethers 100, 102 would thus resemble a cone, such as a badmintonshuttlecock, along a central axis coinciding with a central axis of thecatheter. One or more of the tethers, and particularly the tether 102between the free ends 46, may each form a continuous, hollow, andinflatable space 106 which can hold a fluid. When the inflatable tetherring 102 is inflated with a fluid solution, the free ends 46 areprevented from contacting the tissue of the valve annulus (or othertissue) and instead all tissue contact is with the inflatable ring 102,which presents a smooth, atraumatic contact surface 104 to reduce localtrauma. The fluid solution may comprise a radiographic contrast solutionto permit enhanced fluoroscopic visualization.

While in the detailed descriptions above the systems and methods isdescribed for replacing a native valve, the systems and methods of theinvention could also be used to replace previously-deployed prostheticdevices, such as a previously-deployed prosthetic heart valve which wasfailing due to structural and/or other failure/damage.

While the invention has been described in various embodiments, it is tobe understood that the words which have been used are words ofdescription and not of limitation. Therefore, changes may be made withinthe appended claims without departing from the true scope of theinvention.

1. A catheter for delivering prosthetic valve to a position within apatient, comprising: a catheter proximal portion ending in a catheterproximal end; a catheter distal portion ending in a catheter distal end,the catheter distal portion having an implant holding section configuredto receive a prosthetic valve thereon; a catheter length from thecatheter proximal end to the catheter distal end, wherein the catheterlength is sufficient to reach from a position outside of a patient'sbody to a position within the patient's body; and at least oneextendable positioner configured to be selectively and radially extendedfrom a first position to a second position, wherein in the firstposition the extendable positioner is positioned generally parallel toand against the catheter distal portion with the extendable positionerextending at least partially over the implant holding section, whereinin the second position at least a portion of the extendable positionerextends radially away from the catheter distal portion.
 2. The catheterof claim 1, wherein the extendable positioner comprises a positionerfixed end secured to the catheter distal portion and a positioner freeend, wherein in the first position the positioner fixed end is securedto and adjacent the catheter distal portion while the positioner freeend is radially adjacent the catheter distal portion, wherein in thesecond position the positioner fixed end is secured to and adjacent thecatheter distal portion while the positioner free end is extendedradially away from the catheter distal portion.
 3. The catheter of claim2, wherein the catheter distal portion comprises a radial center, andwherein in the first position the positioner free end is positionedradially away from the radial center by a radial distance of about 2 to5 mm.
 4. The catheter of claim 2, wherein the catheter distal portioncomprises a radial center, and wherein in the second position thepositioner free end is positioned radially away from the radial centerby a distance of about 7 to 18 mm.
 5. The catheter of claim 2, whereinin the second position the positioner free end is positionedlongitudinally aligned with a middle third portion of the implantholding section.
 6. The catheter of claim 5, wherein the catheter distalportion comprises a sheath positioned over the implant holding section,wherein the sheath is configured to be slidingly retracted from theimplant holding section, and wherein the catheter proximal portioncomprises a valve deployment control configured to selectively andslidingly retract the sheath from the implant holding section, whereinthe catheter proximal portion further comprises one or more positionercontrols for selectively extending and retracting the extendablepositioners.
 7. The catheter of claim 5, wherein the implant holdingsection comprises an expandable balloon configured to be expanded from afirst delivery diameter to a second deployment diameter, and wherein thecatheter proximal portion comprises a valve deployment controlconfigured to control expansion of the expandable balloon from the firstdelivery diameter to the second deployment diameter, wherein thecatheter proximal portion further comprises one or more positionercontrols for selectively extending and retracting the extendablepositioner.
 8. A system for replacing a deficient heart valve,comprising: a prosthetic heart valve comprising a radially expandablesupport stent and one or more valve leaflets, wherein the prostheticheart valve is configured to be radially expanded from a deliverydiameter to a deployed diameter; and a catheter comprising a catheterproximal portion ending in a catheter proximal end, the catheter furthercomprising a catheter distal portion ending in a catheter distal end,the catheter having an overall length extending from catheter proximalend to the catheter distal end, wherein the prosthetic heart valve ispositioned on the catheter distal portion, the catheter furthercomprising a plurality of retractable members positioned on the catheterdistal portion, each retractable member comprising a member fixed endsecured to the catheter distal portion at a position adjacent theprosthetic heart valve, each retractable member further comprising aretractable member free end positioned at a distance longitudinallydisplaced with respect to the catheter distal portion such that theretractable member extends at least partially over the prosthetic heartvalve, wherein each retractable member has a first position wherein theretractable member free end is positioned radially adjacent the catheterdistal portion and the retractable member is generally lengthwise andparallel to the catheter distal portion, and wherein each retractablemember has a second position wherein the retractable member free end isradially displaced away from the catheter distal portion such that theretractable member is generally non-parallel with the catheter distalportion.
 9. The system of claim 8, wherein the radially expandablesupport stent of the prosthetic heart valve is a self-expandingstructure comprising a memory material, wherein the radially expandablesupport stent is configured to be biased to expand from an unexpandeddelivery diameter to an expanded deployed diameter, wherein the catheterfurther comprises a sheath over at least part of the catheter distalportion, wherein the prosthetic heart valve is positioned on thecatheter distal portion at a position at least partially underneath thesheath, and the retractable member in the first position extends atleast partially over the sheath.
 10. The system of claim 8, wherein theradially expandable support stent of the prosthetic heart valvecomprises a generally rigid structure, wherein the radially expandablesupport stent is configured to be plastically and radially expanded froman unexpanded delivery diameter to an expanded deployed diameter viaapplication of a radial expansion force, wherein the catheter furthercomprises an expandable balloon positioned on the catheter distalportion, wherein the prosthetic heart valve is positioned on thecatheter distal portion at a position at least partially over theexpandable balloon, and the retractable member in the first positionextends at least partially over the expandable balloon.
 11. The systemof claim 8, wherein the retractable member fixed end is secured to thecatheter at a position proximal of the prosthetic heart valve.
 12. Thesystem of claim 8, wherein the retractable member fixed end is securedto the catheter at a position distal of the prosthetic heart valve. 13.The system of claim 8, wherein the retractable member is biased towardthe second position.
 14. The system of claim 8, wherein the retractablemember free end comprises a radiopaque marker having a radiopaquedensity greater than the average radiopaque density of the rest of theretractable member.
 15. A device for delivering prosthetic valve to aposition within a patient, comprising: a device proximal portion endingin a device proximal end, the device proximal portion comprising adevice handle; a device distal portion ending in a device distal end,the device distal portion having an implant holding section configuredto receive a medical implant thereon; a device usable length from adistal end of the device handle to the device distal end, wherein thedevice usable length is sufficient to reach from a position outside of apatient's body to a position within the patient's body; and at least oneextendable positioner configured to be selectively and radially extendedfrom a first position to a second position, wherein in the firstposition the extendable positioner is positioned generally parallel toand against the device distal portion, wherein in the second position atleast a portion of the extendable positioner extends radially away fromthe device distal portion.
 16. The device of claim 15, wherein theextendable positioner extends at least partially over the implantholding section.
 17. The device of claim 16, wherein the extendablepositioner comprises a positioner fixed end secured to the device distalportion, and a positioner free end configured to be selectively andradially extended away from the device distal portion.
 18. The device ofclaim 17, wherein the positioner free end is positioned along the lengthof the device at a position distal of the positioner fixed end withrespect to the length of the device.
 19. The device of claim 17, whereinthe positioner free end is positioned along the length of the device ata position proximal of the positioner fixed end with respect to thelength of the device.
 20. The device of claim 15, wherein at least oneextendable positioner is configured to be selectively and longitudinallydisplaced from a targeting position adjacent the implant holding sectionto a deployment position longitudinally removed from the implant holdingsection.
 21. The device of claim 15, wherein the extendable positionercomprises a positioner fixed end secured to the device distal portionand a positioner free end, wherein in the first position the positionerfixed end is secured to and adjacent the device distal portion while thepositioner free end is radially adjacent the device distal portion,wherein in the second position the positioner fixed end is secured toand adjacent the device distal portion while the positioner free end isextended radially away from the device distal portion.
 22. The device ofclaim 15, wherein the device distal portion comprises a radial center,and wherein in the first position the positioner free end is positionedradially away from the radial center by a radial distance of about 2 to5 mm.
 23. The device of claim 15, wherein the device distal portioncomprises a radial center, and wherein in the second position thepositioner free end is positioned radially away from the radial centerby a distance of about 7 to 18 mm.
 24. The device of claim 21, whereinin the second position the positioner free end is positionedlongitudinally aligned with a middle third portion of the implantholding section.
 25. The device of claim 24, wherein the device distalportion comprises a sheath positioned over the implant holding section,wherein the sheath is configured to be slidingly retracted from theimplant holding section, and wherein the device proximal portioncomprises a valve deployment control configured to selectively andslidingly retract the sheath from the implant holding section, whereinthe device proximal portion further comprises one or more positionercontrols for selectively extending and retracting the extendablepositioner.
 26. The device of claim 24, wherein the implant holdingsection comprises an expandable balloon configured to be expanded from afirst delivery diameter to a second deployment diameter, and wherein thedevice proximal portion comprises a valve deployment control configuredto control expansion of the expandable balloon from the first deliverydiameter to the second deployment diameter, wherein the device proximalportion further comprises one or more positioner controls forselectively extending and retracting the extendable positioner.